Agitator for lather mixers and the like



May 8, 1951 w. ULKE 2,551,713

AGITATOR FOR LATHER MIXERS AND THE LIKE Filed Dec. 15, 1947 JW gablmmam -mm;

Patented May 8, 1951 AGITATOR FOR LATHER MIXERS AND THE LIKE William Ulke, Genoa, Ill., assignor to John Oster Manufacturing Company, Racine, Wis., a corporation-cf Wisconsin Application December 15, 1947, Serial No. 791,683

1 Claim. (Cl. .259-42) 1 V This invention relates to lather mixing devices and more particularly to an improved agitator for lather mixers. I

Mechanical mixers of the kind now commonly employed in barber shops are designed'to take liquid soap, stored in a'reservoir in the mixer, and whip it in a lather at the turn of a switch, delivering the lather ready for use at the outlet at the front of the mixer. The actual mixing takes place in a confined chamber, and is effected by mechanically agitating the liquid soap with air to whip it into a froth.

It will be seen that in the course of this process it is necessary that both atmospheric air and liquid soap be continually introduced into the mixing chamber, hence the pressure at the air orifice of the mixing chamber must be lower than atmospheric pressure and the pressure at the exit of the soap orifice must likewise be less than the head of liquid on the soap. -On the otherhandmixed lather must flow to the outside of the mixing chamber against atmospheric pressure, hence a pressure ,must be produced in the mixingchambei", at the entranceto the lather discharge passageway or channel, -which is higher than that or" the atmosphere. a

A difference in pressures must thus be produced across the mixing chamber to cause liquid soap and air to flow into the chamber and lather to flow out of it. This function is performed by the agitator which, ideally, should possess the following characteristics:

It should produce a minimum pressure in the mixing chamber consistent with flowing the mixed lather to the outside through a closed passageway 01' channel, since an excessive pressure in the mixing chamber will reduce the rate of flow of both atmospheric air and liquid soap, and therefore of the mixed lather.

The agitator should provide a constant pressure in the mixing chamber, as nearly independent of the speed of the motor as possible.

The agitator should produce as great an air turbulence as possible in the confined space of the mixing chamber, since it is air turbulence which mixes and whips the liquid soap into foam.

With these attributes of the ideal agitator in mind, it is an object of this invention to provide an improved agitator for mechanical lather mixers which will fulfill the requirements of such an agitator in a more satisfactorymanner than previous devices of this type.

Another object of this invention resides in the provision of an unusually efiicient lather mixing agitator of the character described which is simple and inexpensive to construct.

With the above and other objects in view, which will appear as the description proceeds, this invention resides in the novel construct-ion, combination and arrangement-of parts substantially as hereinafter described and more particularly defined by the appended claim, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claim.

The accompanying drawing illustrates one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for thepracticalapplication of the principles thereof, and in which:

Figure 1 is a top view of a mechanical lather mixer embodying the agitator of this invention, portions thereof being broken away; I

Figure 2 is a front elevational view of the mix er, a portion thereof being broken away;

Figure 3 is a perspective view of the agitator per seyand Figure 4 is a cross sectional view through an agitator blade taken along the line i-4 in Figure 3.

Referring now to the accompanying drawings, the numeral 3 designates generally the housingof a lather mixing device, which among other things encloses a liquid soap reservoir 4, the topof which is closed by a removable cover 5.

mixing chamber 5 is located immediately below the soap reservoir and communicates therewith through a duct '5 which enables liquid soap to flow from the reservoir into the mixing chamber, while a standpipe 3 extends upwardly through the soap reservoir and communicates with the mixing chamber at its lower end through an orifice 8 to admit air to the mixing chamber. A lather discharge passageway or channel I 0 leads from the top of the mixing chamber to a spout H at the front of the housing to provide for the delivery of lather, the mouth of the spout being normally closed by a pivoted cover plate !2.

An electric motor l3, also mounted within the housing, has its shaft l l extending into the mixing chamber to drive an agitator [5, the motor being controlled by a switch IS.

The agitator, which constitutes the main feature of this invention, is secured to the shaft #4 of the motor, within the mixing chamber, and has a plurality of blades i'l (preferably three). Each blade comprises a long, narrow strip of light gage metal bent to a substantially semi circular arc in the plane of its fiat side. One end l8 of each blade is secured to a collar 19 provided with a set screw 20 to detachably secure the agitator to the motor shaft, while the other end 2| of each blade is secured to a hub 22. The blades thus lie along meridians of the sphere which they define when the agitator is rotated about the shaft axis.

It will be seen that because the thin edge of each blade strip is oriented in the direction of blade motion, the blade will offer a minimum sur face to air resistance and it will not, therefore, push large volumes of air ahead of it as was the case with previousy used types of agitator blades. The undesirably high pressures in the mixing chambers of previous lather mixers have resulted from the movement of large volumes or" air in front of the fiat part of the agitator which movement continued until the air reached a speed where its centrifugal force produced undesirably high pressure at the periphery of the agitator and along the walls of the mixing chamber.

In order to obtain a mixing turbulence in the chamber whereby the liquid soap is whipped into a foam or lather, a narrow strip or vane 23 at the leading edge of each agitator blade is turned outwardly at an angle of about 30 from the body of the agitator blade. Experiment shows that this strip or vane greatly affects the performance of the agitator since it controls the turbulence of the air in the mixing chamber. Best results have been obtained with a strip approximately 1: inch wide bent at an outward angle of about 30. With a. vane of these dimensions the pressure in the chamber does not vary greatly as the speed of the motor changes.

The importance of this feature resides in the fact that a series wound motor is commonly employed with devices of this type in order to obtain the required speed. Unless a governor is used the agitator encounters little resistance when the motor is turned on and the machine will runtoo fast to produce lather until a sufficient pressure has been built up in the mixing chamber to load the motor enough to slow it down to the speed required to make lather. The

agitator of this invention tends to produce a greater turbulence in the mixing chamber at high speeds without producing a proportionately greater pressure.

In order to facilitate the flow of atmospheric air into the mixing chamber each agitator blade 5 is provided with a larger vane 24 near the end thereof which is secured to the collar I9. Since the air intake orifice 9 is located near the point 4 at which the motor shaft M enters the mixing chamber, the vanes 24 sweep across the mouth of the air intake orifice and serve in eifect as the blades of an intake fan to draw air therethrough.

From the foregoing description taken together with the accompanying drawing it will be seen that the agitator of this invention provides an efficient device for Whipping liquid soap into a lather with a maximum of turbulence in the mixing chamber and without causing undesirably high pressures therein which would preclude the entry into the mixing chamber of the necessary volumes of soap and air.

What I claim as my invention is:

In a lather maker of the type in which a soap solution is mixed with air in a mixing chamber to form a lather, agitating means in said mixing chamber for forming lather and expelling it from the mixing chamber for use, said agitating means comprising: a drive shaft entering the mixing chamber; an agitator having a plurality of blades, each formed from a flat strip bent along its length, in the plane of its flat surface, to a substantially semi-circular arc, said strips having their ends secured together and being arranged about a common axis along meridians coaxial with said axis, each of said blades having a narrow outwardly angled vane along its leading edge; means securing said agitater to the drive shaft for rotation about said axis; an air intake duct in the wall of the mixing chamber having its discharge mouth near the axis about which the agitator turns; and outward extensions on the vanes adjacent to one end of each of said agitator blades positioned to sweep across the mouth of said air intake duct for drawing air into the mixing chamber through the duct.

WILLIAM ULKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 354,934 Raymond Dec. 28, 1387 733,621 Browne July 14-, 1903 948,004 Brown Feb. 1, 1910 1,250,539 Witherbee Dec. 18, 1917 2,052,569 Jensen Sept. 1, 1936 

